The new variety originated from a commercial breeding program under the direction of the inventor, Paul A. Talmadge. The crossing resulting in the new cultivar was made in Fall of 2007, with the seed parent, an unpatented, unnamed proprietary seedling and the pollen parent, also an unpatented, unnamed proprietary seedling. The new variety was discovered by the inventor in April of 2008 at a commercial greenhouse in Lompoc, Calif.
After selecting and isolating the new cultivar, asexual reproduction of the new cultivar ‘IPOSGBRO’ was first performed in a commercial research greenhouse in Lompoc, Calif. during June of 2008. ‘IPOSGBRO’ has since produced several generations and has shown that the unique features of this cultivar are stable and reproduced true to type. Asexual reproduction of the new variety is by vegetative cuttings.